The invention relates in general to the design of combustion engines, particularly compression-ignition internal combustion engines.
Motor manufacturers are faced with the problem of improving engine drivability while at the same time ensuring that the engines meet increasingly severe imposed emissions standards, each change in a standard resulting in significant technical developments and in the use of additional and/or more complicated emissions-control devices which prove to be expensive and which may lead to drops in performance levels.
Manufacturers are looking to increase the drivability of smaller engines which develop increasingly high specific power, notably by resorting to double supercharging in order to increase the amount of air admitted to the engine combustion chamber over a broad range of engine speeds.
This type of engine needs to be developed in such a way that it develops high specific power while at the same time emitting the smallest possible amount of pollutant emissions.